Bros. Points, also known as Special Points in Mario & Luigi: Bowser's Inside Story, are a special statistic featured in that game, Mario & Luigi: Superstar Saga and its 3DS remake, Mario & Luigi: Superstar Saga + Bowser's Minions, as well as Mario & Luigi: Dream Team and Mario & Luigi: Paper Jam. Their abbreviation is often BP.
In Superstar Saga and its remake, Bros. Points appear on a meter within an image featuring red and green balls. To regain lost Bros. Points, Mario or Luigi must drink from a Syrup Jar or use a similar item.
Bros. Points do not appear in Mario & Luigi: Partners in Time, as they were replaced with Bros. Items. They are present in Mario & Luigi: Bowser's Inside Story, albeit grouped into Special Points (see there for details). Bowser utilizes a Special Attack that involves his minions with another variation of Special Points called Brawl Points.
In Dream Team, Bros. Points serve the exact same purpose as before, only this time, they are also used for Luiginary Attacks when in the Dream World. In this game, Bros. Points are represented by the Green Shell icon, which is also used to represent Special Attacks (SP) in Bowser's Inside Story.